Surface-coating Improves Cws Formation Of Low Rank Coal And Washing Waste Water's Role In Cws Formation

Coal is the most important energy resource in China. Most electricity comes from coal combustion. CWS, Coal Water Slurry is a new kind of clean energy which has a higher combustion efficiency and lower emission. CWS can be used as oil in industrial boilers and boilers of electricity plants. CWS is a practical technology for China's clean use of coal.Characters of coal have dominant influence on CWS formation. Shangwan coal exhibits negative properties for slurry formation due to its highly hydrophilic surface which is caused by oxidation sites such as carboxyl, hydroxyl and carbonyl groups. This paper uses four different chemicals and tar to coat the surface of Shangwan coal.Through contact angle measurements at the coal/water interface it is obvious that hydrophobicity of the coal surface is improved a lot. The paper did slurry formation experiments of the surface-coated Shangwan coal. Through which we can get the conclusion that the coating process of Shangwan coal improves its slurry fluidity.This paper uses washing waste water to produce CWS which has a good effect especially to Shenmu coal which can have a high coal concentration as 64%. The oil in the waste water can reduce the pores. This paper studied the effect ofζ, potential on CWS formation. Higher potential means lower viscosity which indicates higher absorption of additives. According to DLVO theory, higherζpotential means more stable the coal water slurry is.